diff --git a/MapControl/Shared/ImageFileCache.cs b/MapControl/Shared/ImageFileCache.cs
index 0640d458..dc0e6bc7 100644
--- a/MapControl/Shared/ImageFileCache.cs
+++ b/MapControl/Shared/ImageFileCache.cs
@@ -326,7 +326,7 @@ namespace MapControl.Caching
 
         private static byte[] ReadAllBytes(FileInfo file)
         {
-            using var stream = file.OpenRead();
+            using var stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
             var buffer = new byte[stream.Length];
             var offset = 0;
 
@@ -340,7 +340,7 @@ namespace MapControl.Caching
 
         private static async Task<byte[]> ReadAllBytes(FileInfo file, CancellationToken token)
         {
-            using var stream = file.OpenRead();
+            using var stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.Read);
             var buffer = new byte[stream.Length];
             var offset = 0;
 
diff --git a/MapControl/Shared/MapPanel.cs b/MapControl/Shared/MapPanel.cs
index 2f1e4db2..e2e69c9c 100644
--- a/MapControl/Shared/MapPanel.cs
+++ b/MapControl/Shared/MapPanel.cs
@@ -1,4 +1,5 @@
-#if WPF
+using System.Linq;
+#if WPF
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Media;
@@ -176,7 +177,7 @@ namespace MapControl
         {
             availableSize = new Size(double.PositiveInfinity, double.PositiveInfinity);
 
-            foreach (FrameworkElement element in Children)
+            foreach (var element in Children.OfType<FrameworkElement>())
             {
                 element.Measure(availableSize);
             }
@@ -188,7 +189,7 @@ namespace MapControl
         {
             if (parentMap != null)
             {
-                foreach (FrameworkElement element in Children)
+                foreach (var element in Children.OfType<FrameworkElement>())
                 {
                     ArrangeChildElement(element, finalSize);
                 }
diff --git a/MapControl/Shared/MapTileLayer.cs b/MapControl/Shared/MapTileLayer.cs
index c7939c6c..7f7b98e2 100644
--- a/MapControl/Shared/MapTileLayer.cs
+++ b/MapControl/Shared/MapTileLayer.cs
@@ -103,7 +103,7 @@ namespace MapControl
             {
                 foreach (var tile in Tiles)
                 {
-                    // Arrange tiles relative to XMin/YMin.
+                    // Arrange tiles relative to TileMatrix.XMin/YMin.
                     //
                     var tileSize = TileSize << (TileMatrix.ZoomLevel - tile.ZoomLevel);
                     var x = tileSize * tile.X - TileSize * TileMatrix.XMin;
diff --git a/MapControl/Shared/WmtsTileMatrixLayer.cs b/MapControl/Shared/WmtsTileMatrixLayer.cs
index a412032c..d2279e0a 100644
--- a/MapControl/Shared/WmtsTileMatrixLayer.cs
+++ b/MapControl/Shared/WmtsTileMatrixLayer.cs
@@ -113,7 +113,7 @@ namespace MapControl
         {
             foreach (var tile in Tiles)
             {
-                // Arrange tiles relative to XMin/YMin.
+                // Arrange tiles relative to TileMatrix.XMin/YMin.
                 //
                 var tileWidth = WmtsTileMatrix.TileWidth;
                 var tileHeight = WmtsTileMatrix.TileHeight;